Summary: This core will carry out animal studies in rhesus macaques in support of this overall IPCP application. The SIV infected rhesus macaque model is a premier model for the study of AIDS pathogenesis, neurAIDS, and vaccine studies in animal models. Dr. Rappaport (Co-Program Director, and Leader, Project 1) and Dr. Tracy Fischer-Smith (Leader Project 2 and Leader Immunopathology Core) have an established history of collaboration with Dr. Mark Lewis (Non Human Primate Core Leader), including two current research projects supported by NIMH (to Dr. Rappaport). The Specific Aim of this Core is to perform supportive in-vivo studies in the rhesus macaque/SIVmac251 system in support of Projects 1, 2, and 3. The core will perform all animal care, viral inoculation, drug dosing and animal manipulations proposed in Projects 1, 2, and 3, of this Program Project and described in the vertebrate animals section of this Core. This core will supply blood, CSF, as well as analysis for viral RNA quantitation and circulating cell populations. The core will perform necropsy tissue isolation, providing specimens to Core B (Immunopathology Core) for further dissection and analysis, for the purpoeses of supporting research within the Projects and this overall IPCP program. The core will interact extensively with the Leaders of the Administrative Core, Core B, as well as Projects 1-3. The Core Leader, Dr. Lewis, will also participate actively in monthly meetings of the executive committee, meetings with the semi- annual Internal Advisory Committee, annual Steering Committee, annual Scientific Advisory Panel, and annual IPCP meeting.